[Protection of Herba Scutellariae Barbatae against hepatotoxicity induced by Rhizoma Dioscoreae Bulbiferae and its mechanism]

This study was conducted to test the protective activity of ethanol extract of Herba Scutellariae Barbatae(SE) against hepatotoxicity induced by Rhizoma Dioscoreae Bulbiferae in mice and its mechanism. SE was orally given to mice at various doses, and ethyl acetate fraction of Rhizoma Dioscoreae Bulbiferae(EF, 450 mg·kg(-1)) was also orally given at the same time. After 11 days, serum levels of alanine/aspartate aminotransferase(ALT/AST), alkaline phosphatase(ALP), total protein(TP) and albumin(ALB) were measured, and liver histological examination was conducted. Liver glutathione(GSH) amount, myeloperoxidase(MPO) activity and serum tumor necrosis factor-α(TNF-α), interleukin-6(IL-6) and interferon-γ(IFN-γ) levels were measured. The expression of heme oxygenase-1(HO-1), inhibitor of kappa B(IκB) and nuclear factor κB(NF-κB) p65 were determined by Western blot. The results showed that SE(200 mg·kg-1) reversed EF-induced changes of serum ALT, AST, ALP, TP and ALB. Liver histology also suggests the protection of SE against EF-induced liver injury. SE reduced the increased MPO activity in liver and TNF-α, IL-6, IFN-γ contents in serum, and blocked the decrease in IκB expression and subsequent increase in phosphorylation and nuclear translocation of p65 induced by EF. EF increased liver GSH amount and heme oxygenase-1(HO-1) protein expression in mice. SE increased liver GSH amount, but decreased the expression of HO-1. All those results suggest that SE alleviates liver injury induced by consecutive administration of EF by alleviating inflammatory injury via inhibiting NF-κB signaling pathway and elevating antioxidant capacity.

Effect of Scutellariae herba extracts in experimental model of skin burns: histological and immunohistochemical assessment

The skin burns are an issue of great interest and seriousness in the public health domain, by their destructive features. Natural medicinal products are extensively used from ancient times, in ethnopharmacology, for the treatment of skin injuries (burns, wounds, ulcerations) due to the local modulation of the cellular response, in terms of emollient, demulcent, astringent, anti-inflammatory, antimicrobial, epithelizing, wound-healing, immunomodulatory and antioxidant effects.

AIM

Histological and immunohistochemical assessment of antiseptic, anti-inflammatory, astringent and cicatrizing effects of Scutellariae (altissimae, galericulatae, hastifoliae) herba extracts administered in the form of 20% topical preparations (cold-creams), in experimental model of third degree skin burns, at Wistar rats. Caffeic acid and chlorogenic acid derivatives were identified in all herbal samples. The most active was the cold-cream with 20% Scutellariae hastifoliae herba soft extract, promoting the neoangiogenesis vessels and granulation tissue. Flavonoids, tannins and polyphenol carboxylic acids are the main active principles responsible for antiseptic, anti-inflammatory, astringent and cicatrizing effects of herbal extracts. Beeswax, from the formulation of cold-creams, acts as emollient, epithelizing, cicatrizing and biostimulator.

Antimicrobial Activity of neo-Clerodane Diterpenoids isolated from Lamiaceae Species against Pathogenic and Food Spoilage Microorganisms

Antimicrobial activity of nineteen neo-clerodane diterpenoids, isolated from the acetone extracts of the aerial parts of Scutellaria and Salvia species (Lamiaceae) were tested against thirteen strains belonging to nine different species of pathogenic and food spoilage bacteria Aeromonas hydrophila, Bacillus cereus, Escherichia coli, Listeria monocytogenes, Proteus vulgaris, Pseudomonas aeruginosa, Pseudomonas fluorescens, Salmonella abony and Staphylococcus aureus as well as against two yeast strains belonging to species Candida albicans. Seven of the evaluated compounds scutalpin A, scutalpin E, scutalpin F, salviarin, splenolide A, splenolide B and splendidin demonstrated antimicrobial activity against used test microbial strains, the rest of the compounds were inactive within the studied concentration range. Among all of the tested compounds the highest antimicrobial activity was detected for scutalpin A against Staphylococcus aureus (MIC 25 µg/mL).

neo-Clerodane Diterpenoids from Scutellaria barbata and Their Inhibitory Effects on LPS-Induced Nitric Oxide Production

Three new neo-clerodane diterpenoids (1-3) along with 12 known compounds (4-15) were isolated from a methanol extract of the aerial parts of Scutellaria barbata. The structures of 1-3 were determined by interpretation of their 1D and 2D NMR spectroscopic data as well as HRESIMS values. All isolated compounds were tested for their inhibitory effects on LPS-induced nitric oxide production in RAW 264.7 macrophages. Compounds 1-4, 7, and 10-12 were found to inhibit nitric oxide production with IC50 values ranging from 20.2 to 35.6 μM.

The Antiviral Effect of Baicalin on Enterovirus 71 In Vitro

Baicalin is a flavonoid compound extracted from Scutellaria roots that has been reported to possess antibacterial, anti-inflammatory, and antiviral activities. However, the antiviral effect of baicalin on enterovirus 71 (EV71) is still unknown. In this study, we found that baicalin showed inhibitory activity on EV71 infection and was independent of direct virucidal or prophylactic effect and inhibitory viral absorption. The expressions of EV71/3D mRNA and polymerase were significantly blocked by baicalin treatment at early stages of EV71 infection. In addition, baicalin could decrease the expressions of FasL and caspase-3, as well as inhibit the apoptosis of EV71-infected human embryonal rhabdomyosarcoma (RD) cells. Altogether, these results indicate that baicalin exhibits potent antiviral effect on EV71 infection, probably through inhibiting EV71/3D polymerase expression and Fas/FasL signaling pathways.

Acylated neo-clerodanes and 19-nor-neo-clerodanes from the aerial parts of Scutellaria coleifolia (Lamiaceae)

Scutefolides A1 and A2, two acylated neo-clerodanes with a 19,18-γ-lactone, scutefolides B1, B2 and C, three 19-nor-neo-clerodanes, together with scutefolides D, E1, E2 and F, four neo-clerodanes, were isolated from the EtOAc-soluble fraction of the aerial parts of Scutellaria coleifolia. Their structures were established on the basis of spectroscopic analysis. The absolute configurations of four of these compounds were elucidated by the CD exciton chirality method. Cytotoxic activities of scutefolides D-F against four cancer cell lines (KB, A549, HeLa, and MCF7) were also evaluated, but they were inactive.

Neo-clerodane diterpenoids from Scutellaria barbata with activity against Epstein-Barr virus lytic replication

Bioassay-guided fractionation was conducted on an EtOAc-soluble extract of the whole plants of Scutellaria barbata, monitored by inhibition of Epstein-Barr virus (EBV) lytic replication. Twenty-six neo-clerodane diterpenoids were isolated, of which 13 are new (1-13, scutolides A-L) and 13 previously known (14-26). The structures of 1-13 were elucidated by analysis of their NMR and MS spectroscopic data. Furthermore, the configurations of the new compounds 1 and 11 were confirmed by single-crystal X-ray diffraction. All of the isolated compounds were evaluated for inhibitory effects against EBV lytic replication. Eleven compounds (3, 4, 6, 11, 12, 15, 16, 17, 20, 22, and 24) exhibited moderate to potent inhibition, with EC50 values from 3.2 to 23.6 μM and selective index (SI) values from 2.1 to 109.2. More specifically, the new compound 4 showed the most potent activity, with EC50 and SI values of 3.2 μM and 46.1, respectively, while compound 24 (EC50 = 16.4 μM) exhibited the highest SI of 109.2. This study is the first to report that neo-clerodane diterpenoids demonstrate significant inhibition against EBV lytic replication.

Using the gene expression signature of scutebarbalactone VN isolated from Scutellaria barbata to elucidate its anticancer activities

Bioassay-guided fractionation led to the discovery of a novel neo-clerodane diterpenoid, scutebarbalactone VN (BalA: 8,13-epoxy-3-en-7-hydroxy-6,11-O- dibenzoyl-15,16-clerodanolide), from the methanol extract of the whole-plant of Vietnamese Scutellaria barbata D. Don. A microarray technique combined with bioinformatic analyses showed that BalA could inhibit cell cycle pathways by downregulating genes such as CDC25A and AURKA. BalA also showed the potential to reactivate downregulated genes in hepatocellular carcinoma cells and genes in antioxidant pathways such as HMOX1 and HSPA1A. Querying Connectivity map 2.0 resulted in a match of the BalA-modulated gene signature with that of 10 known compounds, most of which are currently marketed chemotherapy drugs. The highest matching scores belonged to lomustine, semustine, and withaferin A. Lomustine and semustine were found to alkylate DNA and RNA, while withaferin A inhibits nuclear factor kappa B (NF-κB) activity. A luciferase reporter assay was also conducted on 293/NF-κB human embryonic kidney cells that had been transfected with the NF-κB-luciferase plasmid to verify the anticancer activity of BalA. The assay showed that BalA effectively blocked NF-κB with an IC50 of 38.6 ± 0.05 μM.

In vitro protective effects of Scutellaria litwinowii root extract against H2O2-induced DNA damage and cytotoxicity

BACKGROUND

Despite the wide range of investigations on the therapeutic potentials of herbal extracts in cancer cell lines, there is not usually enough data on their probable effects on normal cells. Recently, both anti-tumoral and anti-oxidant properties of Scutellaria litwinowii extracts have been reported on different cancer cell lines. In the present study, the possible protective effects of S. litwinowii root extracts against cytotoxicity and DNA damage induced by hydrogen peroxide (H2O2) on normal cells were investigated using MTT and Comet assays, respectively.

METHODS

A method of sequential extraction with solvents of different polarities was used to generate methanolic, de-fatted, and dichloromethane fractions. Both MTT and Comet assays were performed here to assess, respectively, changes in cell viability and levels of DNA damage from H2O2. In a pre-treatment regimen, test materials were applied to the cells prior to H2O2 treatment, while in a co-treatment protocol, cells were treated simultaneously with H2O2 and extracts.

RESULTS

In the co-treatment studies, only methanolic extract at 1,000 μg/mL (p<0.001) imparted a significant protective effect as shown in the MTT assay. Pre-treatment of cells for 24 h with different concentrations of the test materials did not lead to any significant protection. Results from the Comet assays in the co-treatment studies suggested a significant (p<0.01) protective effect of the test materials against DNA damage caused by H2O2. However, in the pre-treatment studies, only methanolic extract at ≥500 μg/mL showed a protective effect (p<0.01).

CONCLUSIONS

Considering the probable high levels of phenolic and flavonoid compounds in the methanolic extract, these compounds may impart the noted protective effects of the S. litwinowii root through the scavenging of free radicals.

[Diterpenoids from Scutellaria strigillosa]

By means of preparative HPTLC and column chromatography over silica gel and Sephadex LH-20, nine diterpenoids were isolated and purified from the whole plants of Scutellaria strigillosa. Based on the physico-chemical properties and spectral data, their structures were elucidated as: 6-O-acetyl-7-O-nicotinoylscutebarbatine G(1), 6-O-nicotinoyl-7-O-acetylscutebarbatine G(2), 6,7-di-O-nicotinoylscutebarbatine G(3), scutebarbatine K(4), scutebarbatine B(5), 6-O-acetylscutehenanine A(6), 6-O-nicotinoylbarba- tin A(7), 6,7-di-O-acetoxylbarbatin A(8), scutebarbatine F(9). Compound 1 is a new diterpenoid, and compounds 2-9 were isolated from Scutellaria strigillosa for the first time.

Neo-Clerodane diterpenoids from Scutellaria altissima

Nine neo-clerodane diterpenoids, scutaltisins B-G, scupolin I, scutecolumnin C and 11-epi-scutecolumnin C have been isolated from the acetone extract of the aerial parts of Scutellaria altissima. Scutaltisins B-G are new compounds, whereas scupolin I, scutecolumnin C and 11-epi-scutecolumnin C are reported in this species for the first time.

Effect of light, methyl jasmonate and cyclodextrin on production of phenolic compounds in hairy root cultures of Scutellaria lateriflora

Scutellaria lateriflora (American skullcap) has been used in traditional medicine to treat several medical conditions including nervous disorders and cancer. Previous studies have associated these medicinal properties to flavones present in roots and leaves of this species. In order to develop a production system and study the biosynthesis of these bioactive compounds, hairy root cultures of S. lateriflora were established and line 4 was selected for further studies based on its growth performance in a modified Murashige and Skoog's medium supplemented with 0.5mg/l indole-3-butyric acid. Scanning electron microscopy of the hairy roots showed a high profusion of hairs along the root. Several phenolic compounds, including verbascoside, and the flavones wogonin, baicalein, scutellarein and their respective glucuronides were identified by high performance liquid chromatography-tandem mass spectrometry in the root tissue, but not in the culture medium. Among these compounds, verbascoside accumulated at the highest levels. Interestingly, cultures incubated under continuous light and treated with 15mM methyl-β-cyclodextrin for 24h produced significantly higher levels of the aglycones, baicalein and wogonin, but not scutellarein, compared to cultures incubated under continuous darkness. This work demonstrates that hairy root cultures of S. lateriflora have the biosynthetic capacity to produce known Scutellaria flavones and suggest that light may have a selected regulatory effect on the synthesis or accumulation of these phenolic compounds.

Pheophorbide a, an active compound isolated fromScutellaria barbata, possesses photodynamic activities by inducing apoptosis in human hepatocellular carcinoma

Photodynamic therapy (PDT) is an effective treatment for cancer by inducing apoptosis or necrosis in the target cells. Pheophorbide a (Pa), a chlorophyll derivative, is a photosensitzier which can induce significant anti-proliferative effects in a number of human cancer cell lines. This study investigated the action mechanism of Pa-mediated photodynamic therapy (Pa-PDT) on the human hepatocellular carcinoma, Hep3B cells. Pa-PDT significantly inhibited the growth of Hep3B cells with an IC50 value of 1.5 microM. Intracellular ROS level was increased in Pa-PDT treated cells and the cytotoxic effect could be reversed when ascorbic acid was applied. Pa was found to be localized in the mitochondria and then induced the target cells to undergo apoptosis, which was confirmed by propidium iodide staining and DNA fragmentation assay. Pa-PDT treatment also led to the depolarization of mitochondrial membrane potential (Deltapim) and a release of cytochrome c from mitochondria to the cytosol. The caspase cascade was activated as shown by a significant decrease of procaspase-3 and -9 in Pa-PDT treated cells in a dose-dependent manner. Furthermore, in nude mice model, Pa-PDT treatment could reduce the tumor size by 57% after 14 days treatment.

Skullcap and germander: preventing potential toxicity through the application of hyperspectral imaging and multivariate image analysis as a novel quality control method

Scutellaria lateriflora (skullcap) is a medicinal herb that has a long history of use in the treatment of ailments such as insomnia and anxiety. Commercial herbal formulations claiming to contain S. laterifolia herba have flooded the consumer markets. However, due to intentional or unintentional adulteration, cases of hepatotoxicity have been reported. Possible adulteration with the potentially hepatotoxic Teucrium spp., T. canadense and T. chamaedrys has been reported. In this study, hyperspectral imaging in combination with multivariate image analysis methods was used to differentiate S. laterifolia, T. canadense, and T. chamaedrys raw materials in a non-destructive manner. Furthermore, the ability to detect adulteration of raw materials using the developed multivariate models was also investigated. Chemical images were captured using a shortwave infrared pushbroom imaging system in the wavelength range 920-2514 nm. Principal component analysis was applied to the images to investigate chemical differences between the species. Partial least squares discriminant analysis was used to model pre-assigned class images, and the classification model predicted the levels of adulteration in spiked raw materials. UHPLC-MS as an independent analytical technique was used to confirm chemical differences between the three species. The ability of hyperspectral chemical imaging as a non-destructive technique in the differentiation of the three species was achieved with three distinct clusters in the score scatter plot. A 92.3 % variation in modelled data using PC1 and PC2 was correlated to chemical differences between the three species. Near infrared signals in the regions 1924 nm and 2092 nm (positive P1), 1993 nm and 2186 nm (negative P1), 1918 nm, 2092 nm, and 2266 nm (positive P2), as well as 1993 nm and 2303 nm (negative P2) were identified as containing discriminating information using the loadings line plots. Chemical imaging of spiked samples showed spatial orientation of contaminants within the powdered samples, and percentage adulteration was accurately predicted at levels ≥ 40 % adulteration based on pixel abundance.

[New advance in studies on antimicrobal activity of Scutellaria baicalensis and its effective ingredients]

In recent years, with the constant increase in the population with hypoimmunity, bacterial and fungal infections have been increasing. Due to the drug resistance, clinically optional anti-bacterial and antifungal medicines become increasingly limited. Scutellaria baicalensis, a species of perennial herbaceous plant of scutellaria genus of lamiaceae family, and its effective components have multiple pharmacological effects such as anti-inflammation, anti-oxidation, anti-tumor, anti-microbial. Especially, its remarkable antibacterial and antifungal activities are of great significance to treat the increasing number of cases with drug-fast bacterial and antifungal infections. In this paper, the authors summarized the advance in studies on antibacterial and antifungal effects and mechanisms in recent years on the basis of the domestic and foreign studies on S. baicalensis and its effective ingredients.

Scutellaria baicalensis in stroke management: nature's blessing in traditional Eastern medicine

Scutellaria baicalensis Georgi is the most widely used medicinal plant in traditional Eastern medicine, especially in Chinese medicine. The major phytochemicals isolated from S. baicalensis are flavonoids, glycosides and their glucoronides such as baicalin, baicalein, wogonin etc. More than 30 different kinds of flavonoids are isolated from this plant. S. baicalensis and its flavonoids are reported to have several pharmacological activities, which includes anti-allergic, antioxidant, anti apoptic, anti-inflammatory effects and many more. Recently, S. baicalensis and its isolated flavonoids have been studied for their neuroprotective effects, through a variety of in vitro and in vivo models of neurodegenerative diseases, plausibly suggesting that S. baicalensis has salutary effect as a nature's blessing for neuroprotection. In this review, we are focousing on the neuroprotective effects of S. baicalensis and its flavonoids in ischemia or stroke-induced neuronal cell death. We aimed at compiling all the information regarding the neuroprotective effect of S. baicalensis in various experimental models of cerebral ischemia or stroke.

Scutellaria barbata inhibits angiogenesis through downregulation of HIF-1 α in lung tumor

Hypoxia, a hallmark of many solid tumors, is associated with angiogenesis and tumor progression. Hypoxia-inducible factor-1 (HIF-1) plays a significant role in tumor angiogenesis. In this study, the authors constructed a selective platform to screen the traditional Chinese medicine as anti-angiogenic agent. The authors examined the molecular mechanism by which Scutellaria barbata regulates HIF-1-dependent expression of vascular endothelial growth factor (VEGF), which is an important angiogenic factor. Hypoxia promotes angiogenesis by increasing VEGF expression and secretion. Herein, the expression of VEGF was decreased by treatment with S. barbata in tumor cells. Meanwhile, S. barbata reduced the migration and proliferation of endothelial cells under hypoxic condition. S. barbata inhibited the expression of HIF-1α, as well as phosphorylated their upstream signal mediators AKT. S. barbata significantly inhibited the tumor growth in vivo and immunohistochemical studies in the tumors revealed decreased intratumoral microvessel density. These results suggest that the traditional Chinese medicine therapy using S. barbata, which exerts anti-angiogenic activities, represents a promising strategy for the treatment of tumors.

Scutellaria polysaccharide inhibits the infectivity of Newcastle disease virus to chicken embryo fibroblast

BACKGROUND

To select the antiviral active site of Scutellaria polysaccharide (SPS), safe concentrations of crude total Scutellaria polysaccharide (SPS(t)) and fractional polysaccharide SPS₅₀, SPS₆₀, SPS₇₀ and SPS₈₀ on chicken embryo fibroblast (CEF) were first compared using the MTT method. Then, SPS(t), SPS₅₀, SPS₆₀, SPS₇₀, and SPS₈₀ at five concentrations within the safe concentration, together with Newcastle disease virus (NDV), were added to the cultivating system of CEF in three models: pre-addition of polysaccharide, post-addition of polysaccharide, and simultaneous addition of polysaccharides and NDV after mixing. The effects of SPS on the cellular infectivity of NDV (A₅₇₀ value and the highest viral inhibitory rate) were compared using the MTT method.

RESULTS

At appropriate concentrations, the five polysaccharides could significantly inhibit the infectivity of NDV on CEF. Among the five polysaccharide groups, the SPS₈₀ group exhibited the highest viral inhibitory rate in the three sample-addition modes.

CONCLUSION

This finding indicates that SPS₈₀ possesses the best efficacy as a component of antiviral polysaccharide drug.

Neo-clerodane diterpenoids from Scutellaria galericulata

Four neo-clerodane diterpenoids, neoajugapyrin A, scutegalerins A and B and scutecolumnin C have been isolated from the acetone extract of the aerial parts of Scutellaria galericulata. Neoajugapyrin A and scutecolumnin C are reported in this species for the first time, whereas scutegalerins A and B are new compounds. NMR data of neoajugapyrin A ar e discussed i n detail t o support t he proposed revised structure of ajugapyrin A.

[Using mixture design to optimize preparation technology of gankeshuangqing dispersible tablets]

OBJECTIVE

To study the preparation process and the best prescription of Gankeshuangqing dispersible tablets.

METHODS

In order to select the prescription of Gankeshuangqing dispersible tablets and determine the dissolution, the disintegration time was used as index, single factor method and mixture design were used.

RESULTS

The compositions of Gankeshuangqing dispersible tablets prescription were 50% baicalin, 12.5% andrographolide, CaSO4 23.5%, micro-silica gel 4.1%, and L-HPC 11.3%. The disintegration time was (47 +/- 1) s. Dissolution tests showed that the dissolution rate of this product was higher than that of Gankeshuangqing capsules.

CONCLUSION

The developed Gankeshuangqing dispersible tablets embodies the characteristics of dispersible tablets. The prescription is reasonable and the technology is feasible.

Two new neoclerodane diterpenoids from Scutellaria barbata D. Don growing in Vietnam

Various chromatographic separations of the aerial parts of Scutellaria barbata afforded two new neoclerodane diterpenoids, scutebatas S and T (1 and 2), along with scutebata D (3). Their structures were elucidated by spectroscopic methods including high-resolution electrospray ionization mass spectrometry, 1D and 2D NMR and comparison with the literature values. Compounds 1 and 3 exhibited moderate cytotoxic activities against HL-60 (promyeloblast) human cancer cells. Weak cytotoxic effects toward four tested human cancer cell lines including KB (epidermoid carcinoma), LU-1 (lung adenocarcinoma), MCF7 (breast cancer), and Hep-G2 (hepatoma cancer) were observed for 1 and 3; whereas 2 was inactive on all five tested cell lines.

Differences in pharmacokinetics and anti-inflammatory effects between decoction and maceration of Sanhuang Xiexin Tang in rats and mice

The pharmacokinetics and anti-inflammatory effects of Sanhuang Xiexin Tang, composed of Rhei Radix et Rhizoma, Scutellariae Radix, and Coptidis Rhizoma, prepared by decoction and maceration, were investigated and compared. Rats were orally administered with the decoction and maceration of Sanhuang Xiexin Tang at 30 g/kg. The concentrations of 10 active constituents (berberine, palmatine, jatrorrhizine, coptisine, wogonin, baicalin, wogonoside, emodin, aloe-emodin, and rhein) in plasma were determined by UPLC-MS/MS. Mice were orally administered decoctions and macerations of Sanhuang Xiexin Tang continuously for 7 days at three doses and stimulated with lipopolysaccharide. The plasma concentrations of IL-10 and TNF-α were determined by ELISA. Different preparation methods resulted in significant differences in the pharmacokinetic characteristics of the SXT constituents, especially the protoberberine alkaloids. Maceration decreased the absorption of flavones while promoting the absorption of anthraquinones. Bioavailability of both flavones and anthraquinones increased after administration of macerated Sanhuang Xiexin Tang, especially those of baicalin and rhein, which increased by 3.27 and 7.10 times. Results of ELISA indicated that both the decoction and maceration of Sanhuang Xiexin Tang could significantly increase IL-10 production (p < 0.01) as well as decrease TNF-α production (p < 0.01). Macerated Sanhuang Xiexin Tang has a slightly higher anti-inflammatory effect than the Sanhuang Xiexin Tang decoction. Different preparation methods affected the pharmacokinetic characteristics and anti-inflammatory effects of Sanhuang Xiexin Tang's active constituents.

Ursodeoxycholic acid pretreatment reduces oral bioavailability of the multiple drug resistance-associated protein 2 substrate baicalin in rats

Baicalin is a major bioactive component of Scutellaria baicalensis and a substrate of multiple drug resistance-associated protein 2. Expression of multiple drug resistance-associated protein 2 is regulated by NF-E2-related factor 2. The aim of this study was to explore whether ursodeoxycholic acid, an NF-E2-related factor 2 activator, could influence the oral bioavailability of baicalin. A single dose of baicalin (200 mg/kg) was given orally to rats pretreated with ursodeoxycholic acid (75 mg/kg and 150 mg/kg, per day, intragastrically) or normal saline (per day, intragastrically) for six consecutive days. The plasma concentration of baicalin was measured with the HPLC method. The result indicated that the oral bioavailability of baicalin was significantly and dose-dependently reduced in rats pretreated with ursodeoxycholic acid. Compared with control rats, the mean area under concentration-time curve of baicalin was reduced from 13.25 ± 0.24 mg/L h to 7.62 ± 0.15 mg/L h and 4.97 ± 0.21 mg/L h, and the C(max) value was decreased from 1.31 ± 0.03 mg/L to 0.62 ± 0.05 mg/L and 0.36 ± 0.04 mg/L in rats pretreated with ursodeoxycholic acid at doses of 75 mg/kg and 150 mg/kg, respectively, for six consecutive days. Hence, ursodeoxycholic acid treatment reduced the oral bioavailability of baicalin in rats, probably due to the enhanced efflux of baicalin from the intestine and liver by multiple drug resistance-associated protein 2.

[Recombinant soluble CD40 ligand enhances Wogonin-induced antitumor activity]

OBJECTIVE

To investigate the effect of recombinant soluble CD40 ligand (rsCD40L) on Wogonin mediated antitumor activity in cancer cells and the underlying molecular mechanisms.

METHODS

Cell death was detected based on the release of lactate dehydrogenase (LDH) using a cytotoxicity detection kit. For morphological study of cell death, cells were stained with 50 microg/mL of acridine orange and 50 microg/mL of ethidium bromide and observed and photographed under a fluorescence microscope. Activation of apoptosis pathway was evaluated by Western blot. The effects of pan-caspase inhibitor Z-VAD-FMK and tumor necrosis factor alpha (TNF-alpha) neutralizing antibody on cell death induced by rsCD40L and Wogonin co-treatment were also investigated.

RESULTS

rsCD40L significantly enhanced Wogonin-induced cell death of ovarian cancer cells SKOV3. A dose-dependent synergism was found with a fixed rsCD40L dose (1 microg/mL) and increased concentrations of Wogonin (5 micromol/L-15 micromol/L). rsCD40L and Wogonin co-treated cells showed typical apoptotic morphologies and enhanced activation of caspases pathway. As expected, the pan-caspase inhibitor Z-VAD-FMK inhibited synergistic cell death of rsCD40L and Wogonin co-treated SKOV3 cells. Interestingly, the TNF-alpha neutralizing antibody that blocks TNF-alpha binding to its receptor also significantly suppressed the cell death enhancing effect, indicating that autocrine TNF-alpha played a role of sensitization.

CONCLUSION

rscCD40L sensitizes cancer cells to wogonin-mediated apoptosis, which may involve autocrine of TNF-alpha, and the combination of rsCD40L and Wogonin may have a potential for cancer therapy.

Anti-oxidative and DNA protecting effects of flavonoids-rich Scutellaria lateriflora

Scutellaria lateriflora (American skullcap), a native plant of North America, has been used by Americans and Europeans as a nerve tonic for more than 200 years. In vivo studies have shown anxiolytic activity ofS. lateriflora in animals and humans. However, the neuroprotective mechanisms ofS. lateriflora are not fully understood. Oxidative stress plays a vital role in the neurodegenerative and neuropsychiatric diseases such as anxiety, Alzheimer's disease, depression, and Parkinson's disease. Bioactive compounds present in various medicinal plants neutralize or scavenge toxic free radicals and thus suppress oxidative stress. Therefore, the objective of this study was to investigate the antioxidant effects of S. lateriflora. The antioxidant potential of aqueous or ethanolic extracts of S. lateriflora was determined in mouse brain tissue using various biochemical assays. Protective effects of S. lateriflora against oxidative stress induced DNA fragmentation was determined using plasmid DNA. The ethanolic and aqueous extracts scavenged the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. The ethanolic extract reduced tert-butyl peroxide-induced reactive oxygen species (ROS) and lipid peroxides in the mouse brain homogenates. Furthermore, the ethanolic extract of S. lateriflora protected hydrogen peroxide-UV induced cleavage of supercoiled plasmid DNA. In conclusion, S. lateriflora exhibited significant antioxidant effects. The current findings posit S. lateriflora as one of the potential experimental herbal drugs that should be screened for its therapeutic potential against various oxidative stress associated mental disorders.